Gennari F John, Marano Marco, Marano Stefano
Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont.
Unit of Nephrology and Dialysis, Maria Rosaria Clinic, Pompeii, Italy.
Kidney Med. 2022 Jul 30;4(9):100523. doi: 10.1016/j.xkme.2022.100523. eCollection 2022 Sep.
The acid-base goal of intermittent hemodialysis is to replenish buffers consumed by endogenous acid production and expansion acidosis in the period between treatments. The amount of bicarbonate needed to achieve this goal has traditionally been determined empirically with a goal of obtaining a reasonable subsequent predialysis blood bicarbonate concentration ([HCO ]). This approach has led to very disparate hemodialysis prescriptions around the world. The bath [HCO ] usually chosen in the United States and Europe causes a rapid increase in blood [HCO ] in the first 1-2 hours of treatment, with little change thereafter. New studies show that this abrupt increase in blood [HCO ] elicits a buffer response that removes more bicarbonate from the extracellular compartment than is added in the second half of treatment, a futile and unnecessary event. We propose that changes in dialysis prescription be studied in an attempt to moderate the initial rate of increase in blood [HCO ] and the magnitude of the body buffer response. These new approaches include either a much lower bath [HCO ] coupled with an increase in the bath acetate concentration or a stepwise increase in the bath [HCO ] during treatment. In a subset of patients with low endogenous acid production, we propose reducing the bath [HCO ] as the sole intervention.
间歇性血液透析的酸碱目标是补充内源性产酸及治疗间期扩张性酸中毒所消耗的缓冲物质。传统上，实现该目标所需的碳酸氢盐量是根据经验确定的，目标是使透析前血碳酸氢盐浓度（[HCO₃⁻]）达到合理水平。这种方法导致世界各地的血液透析处方差异很大。在美国和欧洲，通常选择的透析液[HCO₃⁻]会使治疗最初1 - 2小时内血[HCO₃⁻]迅速升高，此后变化很小。新研究表明，血[HCO₃⁻]的这种突然升高引发了一种缓冲反应，该反应从细胞外液中清除的碳酸氢盐比治疗后半段添加的更多，这是一个徒劳且不必要的过程。我们建议研究透析处方的改变，以试图缓和血[HCO₃⁻]的初始升高速率及机体缓冲反应的幅度。这些新方法包括要么采用低得多的透析液[HCO₃⁻]并增加透析液醋酸盐浓度，要么在治疗期间逐步增加透析液[HCO₃⁻]。对于内源性产酸较低的部分患者，我们建议将降低透析液[HCO₃⁻]作为唯一干预措施。
